With the development of national economy and the improvement of people's living standards, on the one hand, China's drinking water sources are seriously polluted; On the other hand, the quality standard of drinking water has been greatly improved. In rainy season, the contents of ammonia, nitrogen, COD, iron, manganese, fluorine, bacteria and turbidity in some water exceed the standard of drinking water. The natural ecological environment is seriously damaged and water resources are seriously polluted.